A commenter recently suggested that I’m “THE WORST Sanders supporter,” and he might be right – it depends on how one defines “support.”

I’ve certainly done more than most to back his candidacy, so in that sense, I’m far from THE WORST. But I’ve never bought into the common view that Sanders would be winning the Democratic primary contest if it weren’t being “rigged” by the DNC and the corporate media. And that belief seems to be the price of admission for many within the Sanders movement.

Of course, it’s obvious that the Democratic establishment prefers Clinton, and the DNC is certainly part of that establishment. Clinton clearly won the “invisible primary.” But I think the DNC’s capacity to swing a primary campaign has been wildly exaggerated by a lot of Sanders supporters.

It’s possible that a less-than-optimal primary schedule could have had a marginal impact on the race, but with months of intense media coverage of the campaigns, that can’t account for much (in FiveThirtyEight’s weighted average of the polls – which many people consider to be the gold standard — Clinton has never led the national race by less than 7.5 percentage points).

But the fatal flaw in this widely accepted narrative that Sanders was robbed is the remarkably stable structure of the race. Some demographic groups within the Democratic coalition have skewed consistently toward Sanders, and others have consistently favored Clinton. And I just can’t come up with a theory of how the actions of the Democratic establishment, or the media, could impact some groups of primary voters but have no effect on others.

The following graphs come from Philip Bump at The Washington Post. The bars represent Sanders’ support, or lack of support, among various groups relative to his overall numbers in each primary contest. They cover all of the states for which exit poll data is available, and the last two bars are averages of the first and last five states to vote, respectfully.

The gender gap isn’t huge, but it’s been consistent and stable from the beginning to the latest contests…

There’s been a very pronounced generational gap throughout the primary season…

And a large and significant gap between white and black voters…

There are other steady divisions as well – for example, Sanders has consistently performed better in states with higher shares of urban voters.

All these groups may consume different media, but there has to be significant overlap, and they’ve certainly been watching — or not watching — the same debates. So how is it that the DNC is able to influence older voters but not younger ones? Men but not women? Blacks but not whites?

Now, you may believe that some of these groups are smarter or better educated than others, but I’d note that we don’t see a consistent difference between the candidates’ support among college and non-college educated voters.

In the comments, I’m sure my fellow Sanders supporters will offer all sorts of creative theories to explain why the groups that tend to skew toward Sanders are immune to the establishment’s Jedi mind tricks – why Millennials say ‘yes, of course these are the droids we’re looking for’ but older voters are like, ‘move along.’

But Occam’s razor suggests a more banal conclusion: That Bernie Sanders, and his platform, resonate most strongly with young voters and urban white liberals, and he hasn’t extended his base far enough into other groups of voters. In other words, among Democratic primary voters, there just aren’t enough of the groups that tend to embrace Sanders by big margins to secure the nomination.